Recently, various types of synthetic resin packing containers which are manufactured by thin-molding have been used for packing and selling eggs.
The synthetic resin packing containers consist of a receiving portion and a lid potion. The receiving portion has egg inserting plates with the same shapes as the eggs to prevent the received eggs from moving. The lid portion has a shape of plate plane. Since the eggs receiving portion has egg inserting plates with the same shapes as the eggs, the surfaces of the received eggs are closely contacted with supporters. Therefore, any external impact to the container is directly applied to the eggs though the supporters, and then the eggs received in the container may be easily damaged. In addition, the synthetic resin has characteristics that it can not be easily dissolved in nature and also, if incinerated, may emit poisonous gases, so that the synthetic resin packing containers would induce environment pollution.
Recently, recycled paper has been used for eggs packing containers instead of the synthetic resin, but the eggs packed in the eggs packing containers made of the recycled paper has been still exposed to damages.
A packing container produced with corrugated cardboard in order to protect the environments from pollution is disclosed in Korean Registered Utility Model No. 20-0188239. The packing container is produced on a single sheet of the corrugated cardboard by means of press processing. Although the packing container according to the Utility Model has much more advantage than the conventional synthetic resin containers, it has still disadvantages in the related industries. The corrugated cardboard used as a packing container has to be assembled into a container though many steps of folding processes. Therefore it takes a lot of time and labor to carry out tho folding processes. The production of the cardboard container has difficulty in time and cost. Furthermore, the production of the cardboard container is not suitable for the production automation.
On the other hand, another packing container made of cardboard was developed by Bergstein in U.S.A., 1962. In the packing container, side portion of the egg was subjected to be held with mechanisms having a series of reverse triangular grooves, which are V-shaped receiving holes. However, the V-shaped receiving holes of the packing container were not suitable for receiving eggs, so that many of eggs were broken in receiving process. And also, in delivery process, some eggs were bumped each other due to the fold lines of the cardboard container.
In addition, a packing container disclosed in U.S. Pat. No. 2,460,020 is shown in FIG. 14. The packing container has large space between receiving holes, and therefore its volume is too much increased. Moreover, it has several wings disposed in its receiving holes so that it is inconvenient for receiving eggs.
In similarity to the container disclosed in the Korean Registered Utility Model, the above mentioned packing containers using corrugated cardboard have also no structure suitable for production automation which is eagerly needed in the related industries.